Writing implement



Jam 4, 1969 HIROYUKI MATSUMOTO I 3,421,323

WRITING IMPLEMENT Filed June 21. 1965 5 6 3 4b 4 \F 3 2 u N I E 46 4a 63 3 6 6 :F g' a :Fg' 4 IE 5 5 e. 5 4b \F I wv-ffig Hiroyuki Motsumoto fKm INVENTOR United States Patent 3,421,823 WRITING IMPLEMENT HiroyukiMatsumoto, Tokyo, Japan, assignor to Dai Nihon Bungu (30., Ltd. FiledJune 21, 1965, Ser. No. 465,467 Claims priority, application Japan, Feb.23, 1965,

ill/13,616; Mar. 10, 1965, 40/18,259, 40/18,260 US. Cl. 401-199 4 ClaimsInt. Cl. B43k /18 ABSTRACT OF THE DISCLOSURE This invention relates towriting implements wherein ink or other (writing fluid is fed to a pointat a rate sufiicient for all writing purposes.

It is the chief object of the invention to provide an implement of thecharacter stated which is reliable in operation under all conditions ofuse, inexpensive to construct and assemble, and a general advance in theart.

Another object is to provide an implement wherein adequate supply ofwriting fluid is afforded at the point, by a specifically constructedcore which at the same time prevents leakage of fluid, blots, and linesthat are too thin or too wide in parts.

Other objects and advantages will become clear to those skilled in theart, after a study of the following detailed description in connectionwith the accompanying drawing.

'In the drawing:

FIGURE 1 is a longitudinal section through an assembled writinginstrument embodying the invention;

FIGURE 2 is a view to an enlarged scale over FIG- URE 1, partly insection, of the core and sealing ring or plug forming a part of theassembly shown upon FIGURE 1;

FIGURE 3 is a cross section in a plane indicated by line AA, FIGURE 2;

FIGURE 4 is a cross section corresponding generally to FIGURE 3, butshowing a somewhat dilferent pattern of capillary grooves;

FIGURE 5 likewise corresponds generally to FIGURE 3, but shows a stilldifferent pattern of grooves;

FIGURE 6 is a view corresponding to FIGURE 2 and partly in section, of amodification of the construction depicted upon FIGURE 2;

FIGURE 7 is a cross section taken in a plane identified by line BB,FIGURE 6;

FIGURE 8 is a view corresponding to FIGURE 2, of still anothermodification; and

FIGURE 9 is a cross section taken in a plane identified by line CC,FIGURE 8.

Referring in detail to the drawing 1, FIGURE 1, identifies the shell orcasing of a writing implement embodying the invention. The forward endof the casing is closed by a plug or tip 4 including a frustro-conicalpart 4a and an integral cylindrical shank 4b, forming a circularshoulder 40 with the base of part 4a. Part 4a is sized and shaped toform a smooth continuation of the tapered surface at the contiguous endof the casing or shell.

The tip or plug 4 is centrally bored to accomodate the ice forward endof a core 3 which has a snug fit within the bore and is fixed therein.The forward end of the core projects forwardly of the adjacent end ofthe plug and is tapered as at 3a to form a scribing or writing point.The core is of relatively porous hard fiber so constructed thatsufiicient ink may permeate longitudinally therealong within the passageprovided by the central bore in plug 4, to point 3a, without, however,permitting any leakage or excessive flow or fluid.

Casing 1 contains an ink-saturated body of felt 2 which, at its rightend as viewed upon FIGURE 1, encompasses the leftward end of core 3 incontact therewith. As shown upon FIGURE 2, the core is provided with twodiametral mutually-normal capillary slits extending from the end insideshell 1 to a location a little inside plug 4. Air cavities 9 and 10within casing 1 compensate for pressure fluctuations.

In operation, ink is received from the saturated body of felt 2 andflows by capillary attraction in and along slit 6 to the solid portionof core 3 within plug 4. Due to the short axial distance from the end ofthe slit within plug 4 to point 3a, a supply of ink sufiicient forwriting is conveyed to the point, without, however, permitting anyleakage from the implement. FIGURE 3 shows the core in cross section andfrom this it is noted that in the preferred construction the two slitsare mutually normal and each extends diametrically completely acrossthat portion of core 3 within shell 1, so that ink may flowunobstructedly from the saturated body of felt tothe terminus of theslits within plug or tip 4, from whence it is conducted through theperous structure of the core, to the point thereof.

FIGURE 4 shows a modification wherein the slits in the core are three innumber, intersecting at the center of the core and each extendingradially thereof, in equiangularly-spaced relation.

FIGURE 5 shows a further modification wherein there is but a single slitextending diametrally across the core. In all forms, the slits terminatesubstantially at the same location in and with respect to the bore intip 4.

At FIGURE 6 I have shown another modification wherein small channels orgrooves 7 are formed longitudinally in that portion of the coreextending from a little to the left of the end of sleeve portion 412 tothe point 3a. These channels, as shown, thus slightly overlap thecontiguous ends of slits 6 and assist in the conduction of ink in andalong the plug or tip portion of the core, to point 321. FIGURE 7, whichis a cross section in a plane indicated by line BB, FIGURE 6, shows thatthe channels may be six in number, equiangularly spaced from the axialplane of the single slit 6. In the particular embodiment of FIG. '6, itis shown that at least one channel 7 communicates with the slit.

In the modification of FIGURES 8 and 9, the channels 7 of FIGURES -6 and7 are replaced by a plurality of small radial bores shown as regularlyspaced in longitudinallyextending rows, which rows are equiangularlyspaced about the core extending from the axial plane of slit 6. Thelongitudinal extent of these rows may be the same as that of thechannels 7 of FIGURES 6 and 7. These pits may be 0.5 to 0.8 mm. indiameter and extend to a short distance only within the core.

I have thus provided a writing implement which fulfills all of theobjects previously stated, and have provided a leak-proof writinginstrument which is inexpensive to produce and reliable and long-livedin operation because of the large quantity of ink available as comparedto an ordinary pen having a reservoir of limited capacity in comparisonto that of the present invention. Only simple milling, drilling andassembly operations are required so that the invention is admirablyadapted to production line and automation procedures.

Due to the fact that the writing fluid flows freely in and along theslits 6 from the end of the core within the casing, right up to andsomewhat within plug 4, the fluid has but a relatively short distance totravel through the permeable core to point 3a. As a result the point iscontinuously supplied with an adequate supply of fluid, while at thesame time, leakage or excessive flow otherwise causing blotting and fatlines, are avoided.

While I have shown the form of the invention presently preferred by me,together with several modifications thereof, various changes of size,shape, alterations and substitutions of equivalents will readily occurto those skilled in the art after a study of the disclosure. Hence thedisclosure should be taken in an illustrative rather than a limitingsense. It is my desire and intention to reserve all modifications withinthe scope of the subjoined claims.

Having now fully disclosed the invention, what I claim and desire tosecure by Letters Patent is:

1. In a writing implement, a hollow tubular casing having an opening inone end, a plug fitting and sealing said opening and extendig a shortdistance only into said casing, there being a central longitudinal borein and through said plug, a fluid-pervious core fitting and securedwithin said bore and projecting at its first end exteriorly of saidcasing to terminate in a writing point, and at its second end projectinginto said casing a distance free and clear of said plug to terminateshort of the mid-length of the casing, a body of ink-saturable fiber insaid casing and encompassing said second end of said core, in contacttherewith, there being at least one capillary slit in said coreextending diametrically and longitudinally thereof, from said second endto a point within said plug, that portion of said core within said plughaving a plurality of regularly angularly spaced channels extendinglongitudinally in the peripheral surface thereof, at least some of saidchannels extending from said capillary slit to said writing point.

2. In a writing implement, a hollow tubular casing having an opening inone end, a plug fitting and sealing said opening and extending a shortdistance only into said casing, there being a central longitudinal borein and through said plug, a fluid-pervious core fitting and securedwithin said bore and projecting at its first end exteriorly of saidcasing to terminate in a writing point, and at its second end projectinginto said casing a distance free and clear of said plug to terminateshort of the mid-length of the casing, a body of ink-saturable fiber insaid casing and encompassing said second end of said core, in contacttherewith, there being at least one capillary slit in said coreextending diametrically and longitudinally thereof, from said second endto a point within said plug, that portion of said core within said plug,having a multiplicity of radially indented pits in regularly-spacedrelation along and about its peripheral surface, the area covered bysaid pits extending to said writing point.

3. A rod-like core of ink-pervious material for a writing implement,said core being formed at one end with a writing point, and having adiametral capillary slit therein, opening through the other end and theperipheral surface thereof, and terminating at a plane about /3 to theover-all length of said core from said other end, there being aplurality of longitudinal channels in the peripheral surface of saidcore, in equiangularly-spaced relation thereabout, said channelsextending from said writing point to a point adjacent the terminal planeof said slit.

4. A rod-like core of ink-pervious material for a writing implement,said core being formed at one end with a writing point, and having adiametral capillary slit therein, opening through the other end and theeripheral surface thereof, and terminating at a plane about /3 to theover-all length of said core from said other end, there being amultiplicity of regularly-spaced radially indented pits in said core andextending over the area thereof from said point to substantially theterminal plane or" said slit.

References Cited UNITED STATES PATENTS 1,166,896 1/1916 Garvey l55632,416,596 2/1927 Rosenthal 15-563 2,453,201 11/1948 Cushman 15-5652,726,416 12/1955 Lepkowski l5561 3,290,717 12/1966 Mizutani 15-5633,203,025 8/1965 Schreur 401199 ROBERT W. MICHELL, Primary Examiner.

